Display device

ABSTRACT

A display device includes a first display panel realizing a first image light of a first resolution; and a second display panel realizing a second image light synchronized with the first image light, the second image light having a second resolution lower than the first resolution, wherein a second virtual image implemented by the second image light is superimposed with a first virtual image implemented by the first image light to implement a virtual reality image.

CROSS REFERENCE TO RELATED APPLICATION

The present application claims the priority of Korean Patent ApplicationNo. 10-2021-0187715 filed on Dec. 24, 2021, which is hereby incorporatedby reference in its entirety for all purposes as if fully set forthherein.

BACKGROUND Field of the Invention

The present disclosure relates to a display device for displaying animage, more particularly, to a display device for displaying a virtualreality (VR).

Discussion of the Related Art

Recently, devices for providing an image to a user using a virtualreality device (VR) have been developed.

A virtual reality refers to an interface between a human and a computerthat makes a specific environment or situation on a computer and makesit as if a user using it is interacting with a real surroundingsituation or environment. The virtual reality allows people to see andmanipulate environments that are difficult to experience on a dailybasis without directly experiencing them.

Such the virtual reality can be applied to fields such as education,advanced programming, remote operation, remote satellite surfaceexploration, exploration data analysis, and scientific visualization.

Here, the virtual reality device is a device to which a virtual realitytechnology is applied to increase a sense of immersion for a single userexperiencing the virtual reality, and in particular, a display devicefor maximizing a sense of visual immersion is considered the mostimportant.

For example, a Head Mounted Display (HMD), a Face Mounted Display (FMD),and an Eye Glasses-type Display (EGD) are representative virtual realitydevices.

Meanwhile, the virtual reality device needs to display a high-resolutionimage in order to prevent a recognition of pixelation, and it is verydifficult to implement a high-resolution image in consideration of ahuman's viewing angle.

SUMMARY

Accordingly, the present disclosure is directed to a display device thatsubstantially obviates one or more of the problems due to limitationsand disadvantages described above.

More specifically, the present disclosure is to provide a display devicewhich can provide a high-resolution virtual reality device.

The present disclosure is also to provide a display device which canprovide a virtual reality device capable of further improving athree-dimensional effect, a sense of reality, and a sense of immersion.

Additional features and advantages of the disclosure will be set forthin the description which follows, and in part will be apparent from thedescription, or may be learned by practice of the disclosure. These andother advantages of the disclosure will be realized and attained by thestructure particularly pointed out in the written description and claimshereof as well as the appended drawings.

To achieve these and other advantages and in accordance with the presentdisclosure, as embodied and broadly described herein, a display deviceincludes a first display panel realizing a first image light of a firstresolution; and a second display panel realizing a second image lightsynchronized with the first image light, the second image light having asecond resolution lower than the first resolution, wherein a secondvirtual image implemented by the second image light is superimposed witha first virtual image implemented by the first image light to implementa virtual reality image.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory and areintended to provide further explanation of the disclosure as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the disclosure and are incorporated in and constitute apart of the present disclosure, illustrate embodiments of the disclosureand together with the description serve to explain the principles of thedisclosure.

In the drawings:

FIG. 1A is a perspective view schematically illustrating a virtualreality device according to an embodiment of the present disclosure;

FIG. 1B is an exploded perspective view of the virtual reality device ofFIG. 1A;

FIGS. 2A and 2B are schematic views illustrating viewing angle ranges ofa human;

FIG. 3 is a schematic diagram illustrating a field of view of first andsecond display panel modules of a virtual reality device according to anembodiment of the present disclosure;

FIG. 4A shows a second virtual image implemented in first, second andsecond, second display panels; c

FIG. 4B shows a first virtual image implemented in first, first andsecond, first display panels;

FIGS. 4C and 4D show virtual reality images implemented through avirtual reality device according to an embodiment of the presentdisclosure;

FIG. 5 is a schematic diagram illustrating a display panel module of avirtual reality device according to an embodiment of the presentdisclosure; and

FIGS. 6 to 12 are schematic views illustrating various display devicemodules of a virtual reality device according to an embodiment of thepresent disclosure.

DETAILED DESCRIPTION

Hereinafter, an embodiment according to the present disclosure isdescribed with reference to the drawings.

FIG. 1A is a perspective view schematically illustrating a virtualreality device according to an embodiment of the present disclosure, andFIG. 1B is an exploded perspective view of the virtual reality device ofFIG. 1A.

As shown in FIGS. 1A to 1B, the virtual reality device 100 may include alens module LM, a display device module DM, a main board MB, a head gearHG, a side frame SF, and a front cover FC.

The display device module DM may include a display panel and a displaypanel driving circuit for driving the display panel to display an inputimage received from the main board MB.

The display panel may be divided into a first display panel module PNL1viewed through a user's left eye and a second display panel module PNL2viewed through a user's right eye. The display device module DM maydisplay image data inputted from the main board MB on the display panelmodules PNL1 and PNL2.

Here, the image data may be 2D/3D image data that implements an image ofvirtual reality (VR).

The main board MB may include a processor that executes a virtualreality software and supplies a left eye image and a right eye image tothe display module DM. Also, although not shown in the drawings, themain board MB may further include an interface module connected to anexternal device, a sensor module, and the like. The interface module maybe connected to the external device through an interface such as auniversal serial bus (USB) or high definition multimedia interface(HDMI).

The sensor module may include various sensors such as a gyro sensor andan acceleration sensor.

The processor of the main board MB may correct the left eye and righteye image data received through the interface module in response to anoutput signal of the sensor module, and transmits the left eye and righteye image data to the display module DM.

The processor may generate a left-eye image and a right-eye imagesuitable for a resolution of the display panel based on a depthinformation analysis result of a 2D image, and transmit the generatedimages to the display module DM.

The lens module LM may be an imaging lens that provides a viewing angleof a screen provided to the user's left and right eyes in a rangegreater than a viewing angle of the user's left and right eyes. Theimaging lens may use a pair of fisheye lenses, which are a kind ofultra-wide-angle lens to widen a viewing angle range of the screen.

The pair of fisheye lenses may include a left eye lens LL disposed infront of the first display panel module PNL1 and a right eye lens RLdisposed in front of the second display panel module PNL2.

The side frame SF may be fixed between the headgear HG and the frontcover FC to secure an internal space in which the lens module LM, thedisplay device module DM, and the main board MB are disposed.

The virtual reality device 100 according to the embodiment of thepresent disclosure may be implemented in a head mounted display (HMD)structure, but is not limited thereto. For example, the virtual realitydevice 100 according to an embodiment of the present disclosure may bedesigned as an EGD (Eye Glasses-type Display) having a glassesstructure.

Here, the virtual reality device 100 according to an embodiment of thepresent disclosure can implement a high-resolution image, therebyimproving a three-dimensional effect, a sense of reality, and a sense ofimmersion.

In this regard, the first and second display panel modules PNL1 and PNL2of the virtual reality device 100 according to the embodiment of thepresent disclosure may be respectively configured to include a first,first display panel 1-1PNL and a first, second display panel 1-2PNL, anda second, first display panel 2-1PNL and a second, second display panel2-2PNL, based on the user's viewing angle.

That is, the display panel may be divided into a first display panelmodule PLN1 for the left eye and a second display panel module PLN2 forthe right eye. In addition, the first display panel module PNL1 for theleft eye may be divided into the first, first display panel 1-1PNL andthe first, second display panel 1-2PNL, and the second display panelmodule PNL2 for the right eye may be divided into the second, firstdisplay panel 2-1PNL and the second, second display panel 2-2PNL.

The first, first and first, second display panels 1-1PNL and 1-2PNL andthe second, first and second, second display panels 2-1PNL and 2-2PNLmay have different resolutions based on the viewing angles of the user'sleft and right eyes.

Here, referring to FIGS. 2A and 2B, a human horizontal viewing anglerange is 220 degrees or more, which forms an entire viewing range ofboth eyes. However, the actual binocular viewing range is 120 degrees inmost cases, depending on a geometry of a human's nose. In addition, arange of color discrimination is 60 degrees, a range of symbolrecognition is 40 degrees, and a range of text recognition is 20degrees, which are formed in small viewing angle ranges. A Fovea rangewhich is the most clearly recognizable viewing range is formed muchsmaller by 2 to 3 degrees.

In addition, a human vertical viewing angle range is similar to thehorizontal viewing angle range. However, the vertical viewing anglerange has an asymmetrical entire viewing range of 50 degrees upward and70 degrees downward from a reference line RL extending in a Z-axisdirection as the horizontal direction from the eye.

The human vision is a dynamic concept and is best explained whenconsidering a limited or unconstrained range of eye movement, and anunconstrained eye movement does not cause eye strain and allows for asteady gaze and consequent accommodative reflexes.

This may vary depending on a human age. However, an eye rotation rangein which an eye movement is constrained is formed as large as 25 degreesupward and 30 degrees downward from the reference line RL, but anunconstrained eye rotation range in which an eye is not constrainedbecomes much smaller at 15 degrees upward and 20 degrees downward fromthe reference line RL.

As such, an appropriate central region of the human vertical andhorizontal viewing angle ranges is about 15 to 45 degrees, and anappropriate central region of the Fovea range is about 30 degrees.

Therefore, the virtual reality device 100 according to the embodiment ofthe present disclosure may include the first and second display panelmodules PNL1 and PNL2 such that the first, first and second, firstdisplay panels 1-1PNL and 2-1PNL each having a first resolution as ahigh resolution are located at the appropriate central regionscorresponding to the Foveas of the eyes, and the first, second andsecond, second display panels 1-2PNL and 2-2PNL each having a secondresolution lower than the first resolution are located at peripheralregions corresponding to peripheral viewing angles other than theappropriate central regions.

In this case, the first, first and second, first display panels 1-1PNLand 2-1PNL having the first resolution may be positioned within 30degrees (±15 degrees) as the appropriate central region ranges of thevertical and horizontal viewing angles, and the first, second andsecond, second display panels 1-2PNL and 2-2PNL having the secondresolution may be positioned within the range of 40 to 100 degrees asthe peripheral regions.

Accordingly, the virtual reality device 100 according to an embodimentof the present disclosure may implement a high-resolution image. Inaddition, the virtual reality device 100 may match resolutions accordingto human viewing angles so that little or no pixelation in which a shapeof a pixel is recognized in a virtual image is recognized, therebypreventing recognition of the pixelation from occurring.

Accordingly, a three-dimensional effect, a sense of reality and a senseof immersion of an image implemented in the virtual reality device 100can be improved.

FIG. 3 is a schematic diagram illustrating a field of view of first andsecond display panel modules of a virtual reality device according to anembodiment of the present disclosure. FIG. 4A shows a second virtualimage implemented in first, second and second, second display panels,and FIG. 4B shows a first virtual image implemented in first, first andsecond, first display panels.

FIGS. 4C and 4D show virtual reality images implemented through avirtual reality device according to an embodiment of the presentdisclosure.

As shown in FIG. 3 , the first, second and second, second display panels1-2PNL and 2-2PNL each having the second resolution are positionedwithin 40 to 100 degrees, which is the peripheral region range of eachof the right eye and left eye. the first, first and second, firstdisplay panels 1-1PNL and 2-1PNL each having the first resolution arepositioned within 30 degrees (±15 degrees) which is the central regionrange of each of the right eye and left eye.

Here, images output from the first and second display panel modules PNL1and PNL2 are synchronized and basically output based on the sameoriginal image. As shown in FIG. 4A, each of the first, second andsecond, second display panels 1-2PNL and 2-2PNL implements a secondvirtual image having a second resolution, and in this case, the secondvirtual image may have a definition of about 60 to 80%.

In this case, the second virtual image may be divided into a region Acorresponding to a center and a region B defined along an edge of theregion A.

In addition, as shown in FIG. 4B, each of the first, first and second,first display panels 1-1PNL and 2-1PNL implements a first virtual imagewhich is the same image as the second virtual image but has a firstresolution.

In this case, the first virtual image has a definition of 100% clarity,so that the first resolution is higher than the second resolution.

As described above, in the virtual reality device (100 of FIG. 1B)according to the embodiment of the present disclosure, the secondvirtual image having the second resolution is implemented within 40 to100 degrees which is the peripheral region range, and the first virtualimage having the first resolution is implemented within 30 degrees (±15degrees) which is the central region range.

At this time, as the first virtual image falls within 30 degrees (±15degrees) of the central region range, the first virtual image isimplemented only at a region only corresponding to the region A of thesecond virtual image that falls within 40 to 100 degrees as theperipheral region range, and is cut out at a region corresponding to theregion B of the second virtual image.

Therefore, to a user who wears the virtual reality device (100 of FIG.1B) according to an embodiment of the present disclosure, the image ofthe region B of the second virtual image are superimposed (oroverlapped) along the edge of the first virtual image with the firstvirtual image as a center, and the virtual reality image in which thefirst and second virtual images are mixed is provided, as shown in FIG.4C.

Here, in the process of mixing the first and second virtual images, thesecond virtual image allows the region A to be cut out, therebypreventing the first virtual image and the second virtual image frominterfering with each other.

In the virtual reality image provided to the user, the boundary betweenthe first virtual image and the second virtual image may be blurred.More precisely, the edge of the first virtual image may be blurredcorresponding to the second virtual image.

Accordingly, as shown in FIG. 4D, the boundary between the first virtualimage and the second virtual image may not be recognized.

In particular, by setting the edge region of the first virtual image tohave a resolution between the resolution of the first virtual image andthe resolution of the second virtual image, the boundary between thefirst virtual image and the second virtual image may not be recognized.

Therefore, the virtual reality image implemented by mixing the first andsecond virtual images may have more naturalness as if it were a singleimage.

Here, the first virtual image is preferably implemented to have aresolution of at least 1000 PPI or higher, and the second virtual imageis preferably implemented to have a resolution of about 100 PPI orhigher.

Looking at this in more detail, a distance between the user's both eyesand the display panels 1-1PNL, 1-2PNL, 2-1PNL and 2-2PNL is very short,about several centimeters. The reason of arranging the display panels1-1PNL, 1-2PNL, 2-1PNL and 2-2PNL adjacent to both eyes of the user isthat an image is provided to be wider than the user's field of view sothat the image feels the same as a real space.

At this time, simply placing the display panel 1-1PNL, 1-2PNL, 2-1PNLand 2-2PNL close to the user's eyes is equivalent to looking at thescreen very closely, so the image cannot be recognized properly. Inparticular, edge portions of the display panels 1-1PNL, 1-2PNL, 2-1PNLand 2-2PNL are also recognized, thereby reducing a sense of reality. Inorder to give a sense of reality beyond simply placing the displaypanels 1-1PNL, 1-2PNL, 2-1PNL and 2-2PNL close to the eyes, the lensmodule (LM of FIG. 1 ) may be disposed between the display panels PNL,1-2PNL, 2-1PNL and 2-2PNL and the user's both eyes.

Accordingly, when the user sees the images implemented in the displaypanels 1-1PNL, 1-2PNL, 2-1PNL and 2-2PNL through the lens module (LM ofFIG. 1B), the user see the images magnified 4 to 5 times than the actualimages displayed in the display panels 1-1PNL, 1-2PNL, 2-1PNL and2-2PNL. When resolutions of the display panels 1-1PNL, 1-2PNL, 2-1PNLand 2-2PNL is low in such the close-view and lens module (LM of FIG. 1B)application environment, a pixelation is recognized and a reality of theimage is reduced.

Accordingly, it is preferable that the virtual reality device (100 ofFIG. 1B) has a resolution of 2K or higher, where K means 1000. Forexample, 1K means a resolution of about 1000 horizontal pixels, 2K meansa resolution of about 2000, 4K means a resolution of about 4,000, and 8Kmeans a resolution of about 8,000 pixels.

Here, even with the same resolution, a pixel size is different dependingon a size of the display panels 1-1PNL, 1-2PNL, 2-1PNL and 2-2PNL. Forexample, between a 2.5-inch display and a 5-inch display panel havingthe same resolution of 2K, pixel sizes thereof have a difference thatcannot be ignored.

Therefore, in addition to a resolution, a pixel density also needs to beconsidered. The pixel density uses a unit called PPI (Pixel Per Inch),which means a number of pixels per inch.

For example, if 1K resolution is implemented on a 5-inch display panel,a horizontal length of the display panel is 4 inches, and thus thedisplay panel has a resolution of 250 PPI. If 2K resolution isimplemented on a 5-inch display panel, the display panel has aresolution of 500 PPI. Meanwhile, if 1K resolution is implemented on a2.5-inch display panel, a horizontal length becomes 2 inches, and thusthe display panel has a resolution of 500 PPI. Similarly, if 2Kresolution is implemented on a 2.5-inch display panel, the display panelhas a resolution of 1000 PPI.

Here, it is preferable that in order to increase sense of reality andimmersion, the virtual reality device (100 of FIG. 1B) according to theembodiment of the present disclosure has a high resolution, and a pixelsize small enough not to be recognized by a proximity arrangementstructure.

In this case, at a resolution of 1000 PPI or less, a pixelation occursin which a shape of a pixel is recognized. Therefore, in the virtualreality device (100 of FIG. 1B) according to the embodiment of thepresent disclosure, it is preferable that the first virtual imageimplemented within 30 degrees (±15 degrees), which is the range of thecentral region of the user's eyes, has a high resolution of 1000 PPI orhigher.

Through this, in the virtual reality device (100 of FIG. 1B) accordingto the embodiment of the present disclosure, the pixelation is preventedby displaying a high-resolution image, thereby improving athree-dimensional effect, a sense of reality and a sense of immersion.

In addition, by implementing the second virtual image within 40 to 100degrees, which is the peripheral region range, to have 100 PPI, thevirtual reality device (100 of FIG. 1B) according to the embodiment ofthe present disclosure may only need to consider distances between theboth eyes and the display panels 1-1PNL, 1-2PNL, 2-1PNL and 2-2PNLcorresponding to the peripheral region range. Thus, since the size ofthe virtual reality device (100 of FIG. 1B) does not increase eventhough a high resolution is implemented, light weight and thinness canalso be implemented.

FIG. 5 is a schematic diagram illustrating a display panel module of avirtual reality device according to an embodiment of the presentdisclosure, and also shows an optical path therein.

Here, images respectively output from the first and second display panelmodules (PNL1 and PNL2 of FIG. 1B) are synchronized and basically outputbased on the same original image. Hereinafter, for convenience ofdescription, the first display panel module PNL1 is described as anexample.

As shown in FIG. 5 , the first display panel module PNL1 may include thefirst, first and first, second display panels 1-1PNL and 1-2PNL, a lightguide part 111 and a semi-transmissive (or transflective) part 113.

The light guide part 111 may be positioned in front of the user's eyes.The light guide part 111 may have a lens shape that provides a field ofview to the user, and may be formed of a material being transparent ortranslucent.

Therefore, the light guide part 111 may be formed of a plastic materialsuch as polymethylmethacrylate (PMMA), which is an acrylic transparentresin as one of transmissive materials that can transmit light, or oneselected from a polycarbonate (PC) series, a polystyrene (PS) series anda polymethacrylstyrene (MS) series. It is preferable to use PMMA whichhas excellent transparency, weather resistance and coloration andinduces light diffusion when light is transmitted.

Here, the light guide part 111 may include a front surface 111 a, a rearsurface 111 b, and a plurality of side surfaces 111 c and 111 dconnecting the front surface 111 a and the rear surface 111 b. In astate in which the virtual reality device (100 of FIG. 1B) is worn onthe user's eyes, the front surface 111 a is defined as an outer surfaceof the light guide part 111 i.e., a surface not facing the user's eyes,and the rear surface 111 b is defined as an inner surface of the lightguide part 111 i.e., a surface facing the eyes.

The first, first display panel 1-1PNL may be positioned outside one sidesurface 111 c of the light guide part 111, and the first, second displaypanel 1-2PNL may be positioned outside the front surface 111 a of thelight guide part 111.

The light guide part 111 may reflect and guide a first image light L1 ofthe first, first display panel 1-1PNL at least once or more. The lightguide part 111 may totally reflect the first image light L1 incidenttherein to guide the first image light L1 toward the user's eyes.

The first, first and first, second display panels 1-1PNL and 1-2PNL,which are components for generating a virtual image, may be implementedas a display device, for example, a liquid crystal display device (LCD),a plasma display panel device (PDP), a field emission display device(FED), an electroluminescence display device (ELD), an organic lightemitting diode (OLED), an LCoS (liquid crystal on silicon substrate), anOLEDoS (organic light emitting device on silicon substrate), or an LEDoS(light emitting diode on silicon substrate).

In particular, the virtual reality device (100 in FIG. 1B) according tothe embodiment of the present disclosure may preferably include thefirst, first and first, second display panels 1-1PNL and 1-2PNLconfigured using the OLEDoS which is formed using a wafer-basedsemiconductor process and are thus realized in a small size with a highresolution.

Although not shown in the drawings, in more detail, in the first, firstand first, second display panels 1-1PNL and 1-2PNL made of OLEDoS adriving thin film transistor may be formed for each pixel area on thewafer substrate. Further, a first electrode connected to each drivingthin film transistor, an organic light emitting layer emitting light onthe first electrode, and a second electrode on the organic lightemitting layer may be formed.

The organic light emitting layer may emit a white light. Alternatively,the organic light emitting layer may emit a red, green, or blue lightfor the corresponding pixel area.

The first and second electrodes and the organic light emitting layerformed therebetween may constitute a light emitting diode. In the first,first and first, second display panels 1-1PNL and 1-2PNL, the firstelectrode may be configured as an anode, and the second electrode may beconfigured as a cathode.

The first, first and first, second display panels 1-1PNL and 1-2PNL madeof such the OLEDoS may generate the first and second virtual images,respectively.

Accordingly, the first and second image lights L1 and L2 output from thefirst, first and first, second display panel 1-1PNL and 1-2PNL areincident into the light guide part 111. The first image light L1implemented from the first, first display panel 1-1PNL is guided by thesemi-transmissive part 113 positioned inside the light guide part 111.

The semi-transmissive part 113 may include a reflective surface 113 athat transmits a part of light and reflects another part of the light.The first image light L1 incident from the first, first display panel1-1PNL is reflected by the reflective surface 113 a to be emitted towardthe rear surface 111 b of the light guide part 111, so that the firstimage light L1 reaches the user's eye.

The second image light L2 incident from the first, second display panel1-2PNL passes through the reflective surface 113 a and is emitted towardthe rear surface 111 b of the light guide part 111, so that the secondimage light L2 also reaches the user's eye.

Accordingly, the user can see the first image light L1 output by thefirst, first display panel 1-1PNL and the second image light L2 outputby the first, second display panel 1-2PNL.

At this time, the first image light L1 reaches within 30 degrees (±15degrees), which is the central region range of the user's eye, and isformed of a first virtual image having a first resolution.

In addition, the second image light L2 reaches within 40 to 100 degrees,which is the peripheral region range of the user's eye, and is formed ofa second virtual image having a second resolution lower than the firstresolution.

Accordingly, the virtual reality image in which the second virtual imageis superimposed along the edge of the first virtual image with the firstvirtual image as the center is provided to a user wearing the virtualreality device (100 of FIG. 1B) according to the embodiment of thepresent disclosure.

Accordingly, the virtual reality device (100 of FIG. 1B) according tothe embodiment of the present disclosure can deliver a high-resolutionimage to the user to prevent an occurrence of pixelation, therebyimproving a three-dimensional effect and a sense of reality, and a senseof immersion.

In addition, by making the second virtual image implemented within 40 to100 degrees of the peripheral region range have a lower resolution thanthe first virtual image, the user is substantially provided with ahigh-resolution virtual reality image while a size of the virtualreality device (100 of FIG. 1B) does not increase, so the user can use alightweight and thin virtual reality device (100 of FIG. 1B).

In this case, an optical lens part (not shown) may be further providedbetween the light guide part 111 and the first, first display panel1-1PNL. The optical lens part may serve to change a path of the firstimage light L1. In this regard the optical lens part may include atleast one projection lens capable of diffusing or condensing light usinga refractive index such as a convex lens or a concave lens, and/or atleast one collimation lenses capable of emitting incident light inparallel.

Accordingly, the first image light L1 output from the first, firstdisplay panel 1-1PNL is diffused or condensed through the optical lenspart to reach the reflective surface 113 a of the semi-transmissive part113.

In addition, since the reflective surface 113 a of the semi-transmissivepart 113 has an aspherical shape toward the rear surface 111 b of thelight guide part 111, the first image light L1 can be efficientlyfocused without distortion.

In addition, the virtual reality device (100 of FIG. 1B) according tothe embodiment of the present disclosure may include variousconfigurations in addition to the display panel module PNL1 shown inFIG. 5 . Hereinafter, in the virtual reality device (100 of FIG. 1B)according to the embodiment of the present invention, various examplesof the display panel modules PNL1 are described.

FIGS. 6 to 12 are schematic views illustrating various display devicemodules of a virtual reality device according to an embodiment of thepresent disclosure, and also show optical paths therein.

As shown in FIG. 6 , a prism 201 may be positioned in front of theuser's eye, and the prism 201 may diverge a light. Thus, a first imagelight L1 implemented from a first, first display panel 1-1PNL isreflected by the prism 201 so that the first image light L1 reaches theuser's eye within 30 degrees (±15 degrees), which is the appropriatecentral region range of a viewing angle, and a second image light L2implemented from a first, second display panel 1-2PNL positioned behindthe prism 201 reaches the user's eyes within 40 to 100 degrees which isthe peripheral region range.

In addition, as shown in FIG. 7 , a plurality of semi-transmissive parts113 may be configured in front of the user's eye.

Therefore, a first image light L1 of a first, first display panel 1-1PNLis separated by each semi-transmissive part 113 so that the separatedfirst image light L1 reaches the user's eye, thereby further achievingan effect of expanding an eyebox.

In addition, as shown in FIG. 8 , a beam splitter 203 may be positionedin front of the user's eye.

Here, a surface facing the user's eye is defined as a front surface 203a of the beam splitter 203, a surface located at a rear of thereof isdefined as a rear surface 203 b, and side surfaces 203 c connecting thefront surface 203 a and the rear surface 203 b are defined. A first,first display panel 1-1PNL may be positioned on one side surface 203 cof the beam splitter 203, and a first, second display panel 1-2PNL maybe positioned on the rear surface 203 b of the beam splitter 203.

Since the beam splitter 203 reflects a part of light and transmits apart of the light, the beam splitter 203 reflects a first image light L1of the display panel 1-1PNL to make the first image light L1 reach theuser's eye. Further, the beam splitter 203 transmits a second imagelight L2 of the first, second display panel 1-2PNL to make the secondimage light L2 reach the user's eye.

In this case, a half mirror or a polarization reflection mirror may bepositioned instead of the beam splitter 203.

The half mirror may include a semi-transmissive material. For example,the half mirror may include a thin metal film such as magnesium (Mg),silver (Ag), or aluminum (Al).

In addition, the polarization reflection mirror is a selective polarizerthat transmits linearly polarized light in a first direction andreflects linearly polarized light in a second direction, and may beconfigured with a wire grid polarizer.

Also, as shown in FIG. 9 , it may be configured that a first image lightL1 implemented from a first, first display panel 1-1PNL passes throughthe beam splitter 203, then is reflected by the mirror 205 positioned onthe other side of the beam splitter 203, and reaches the user's eye.

In addition, as shown in FIG. 10 , a plurality of beam splitters 203 maybe provided so that a first image light L1 implemented from a first,first display panel 1-1PNL is divided into a plurality of lights, whichare reflected or transmitted by the beam splitters 203 and reach theuser's eye.

In addition, as shown in FIG. 11 , a TIR (Total Internal Reflection)free-form curved surface prism 207 may be provided.

The TIR free-form curved prism 207 is positioned so that a concavereflective surface 207 a faces the user's eye, and thus a first imagelight L1 implemented in a first, first display panel 1-1PNL is directedto the user's eye. In this case, a second image light L2 implemented ina first, second display panel 1-2PNL passes through the TIR free-formcurve surface prism 207 as it is and is transmitted to the user's eye.

Also, as shown in FIG. 12 , a display device module PNL1 of the virtualreality device according to the embodiment of the present disclosure maybe formed of a holographic optical element HOE.

That is, a first light guide plate 213 a including first and secondoptical pattern parts 211 a and 211 b for diffracting a first colorlight C1 among a first image light L1 implemented in a first, firstdisplay panel 1-1PNL, and a second light guide plate 213 b includingthird and fourth optical pattern parts 215 a and 215 b for diffractingsecond and third color lights C2 and C3 among the first image light L1are provided.

The first to fourth optical pattern parts 211 a, 211 b, 215 a and 215 bmay diffract the incident light to change the path of the light. Each ofthe first to fourth optical pattern parts 211 a, 211 b, 215 a and 215 bmay include a pattern recorded therein so that an angle of diffractionis determined according to a wavelength of light.

Accordingly, the first image light L1 implemented from the first, firstdisplay panel 1-1PNL is diffracted by the first to fourth opticalpattern parts 211 a, 211 b, 215 a and 215 b to be transmitted to theuser's eye. In this case, the second image light L2 implemented from thefirst, second display panel 1-2PNL is transmitted through theholographic optical element HOE to the user's eye.

Accordingly, a user wearing the virtual reality device 100 (100 of FIG.1B) according to the embodiment of the present disclosure can see thefirst image light L1 output from the first, first display panel 1-1PNLand the second image light L2 output from the first, second displaypanel 1-2PNL. In this case, the user can receive the first virtual imageof the first resolution within 30 degrees (±15 degrees) as the centralregion range by the first image light L1, and the second virtual imageof the second resolution lower than the first resolution within 40 to100 degrees as the peripheral region range by the second image light L2.

Accordingly, the user is provided with a virtual reality image in whichthe second virtual image is superimposed along the edge of the firstvirtual image with the first virtual image as the center.

Accordingly, the virtual reality device (100 of FIG. 1B) according tothe embodiment of the present disclosure can deliver a high-resolutionimage to the user prevent pixelation, thereby improving athree-dimensional effect, a sense of reality and a sense of immersion.

In addition, by making the second virtual image implemented within 40 to100 degrees of the peripheral region range have a lower resolution thanthe first virtual image, the user is substantially provided with ahigh-resolution virtual reality image while the size of the virtualreality device (100 of FIG. 1B) does not increase, so that the user canuse a lightweight and thin virtual reality device (100 of FIG. 1B).

Meanwhile, in the above description, it is illustrated and describedthat the first virtual image and the second virtual image are cut out ina superimposing region in the process of mixing the first and secondvirtual images. However, the first and second virtual images may beimplemented by superimposing each other without a separate cut-out.

That is, the first virtual image may be superimposed as an informationimage on the second virtual image, and the information image may be abasic information such as weather and time, or may be composed ofvarious information of various peripheral devices.

It will be apparent to those skilled in the art that variousmodifications and variation can be made in the present disclosurewithout departing from the spirit or scope of the disclosure. Thus, itis intended that the present disclosure cover the modifications andvariations of this disclosure provided they come within the scope of theappended claims and their equivalents.

What is claimed is:
 1. A display device, comprising: a first displaypanel realizing a first image light of a first resolution; and a seconddisplay panel realizing a second image light synchronized with the firstimage light, the second image light having a second resolution lowerthan the first resolution, wherein a second virtual image implemented bythe second image light is superimposed with a first virtual imageimplemented by the first image light to implement a virtual realityimage.
 2. The display device of claim 1, wherein the virtual realityimage includes a region A of a center portion corresponding to 30degrees i.e., ±15 degrees which is a central viewing angle region rangeof a user's eye, and a region B which corresponds to 40 to 100 degreeswhich is a peripheral viewing angle region range of the user's eye andsurrounds an edge of the region A.
 3. The display device of claim 2,wherein the virtual reality image has the first virtual imageimplemented in the region A, and the second virtual image implemented inthe region B.
 4. The display device of claim 3, wherein the secondvirtual image is cut out corresponding to the region A, and the firstvirtual image is cut out corresponding to the region B.
 5. The displaydevice of claim 3, wherein a boundary portion between the first virtualimage and the second virtual image of the virtual reality image isblurred
 6. The display device of claim 5, wherein an edge of the firstvirtual image is blurred.
 7. The display device of claim 3, wherein anedge region of the first virtual image has a resolution between thefirst resolution and the second resolution.
 8. The display device ofclaim 1, wherein the first resolution is 1000 PPI or higher, and thesecond resolution is 100 PPI or higher.
 9. The display device of claim2, further comprising: a light guide part reflecting and guiding thefirst image light at least once; and a semi-transmissive part reflectingthe first image light guided by the light guide part to outside thelight guide part, wherein the first display panel is positioned on oneside surface of the light guide part in a length direction of the lightguide part, and the second display panel is positioned in front of thelight guide part.
 10. The display device of claim 9, further comprisingan optical lens part positioned between the light guide part and thefirst display panel.
 11. The display device of claim 1, wherein each ofthe first and second display panels includes: a substrate including aplurality of pixel areas; a first electrode disposed in each pixel areaon the substrate; an organic light emitting layer disposed on the firstelectrode; and a second electrode disposed on the organic light emittinglayer.